// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_
#define CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_

#include <stdint.h>

#include <string>

#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "content/common/content_export.h"
#include "net/base/ip_address.h"
#include "third_party/webrtc/base/asyncresolverinterface.h"

namespace base {
class SingleThreadTaskRunner;
} // namespace base

namespace content {

class P2PSocketDispatcher;

// P2PAsyncAddressResolver performs DNS hostname resolution. It's used
// to resolve addresses of STUN and relay servers.
class P2PAsyncAddressResolver
    : public base::RefCountedThreadSafe<P2PAsyncAddressResolver> {
public:
    typedef base::Callback<void(const net::IPAddressList&)> DoneCallback;

    P2PAsyncAddressResolver(P2PSocketDispatcher* dispatcher);
    // Start address resolve process.
    void Start(const rtc::SocketAddress& addr,
        const DoneCallback& done_callback);
    // Clients must unregister before exiting for cleanup.
    void Cancel();

private:
    enum State {
        STATE_CREATED,
        STATE_SENT,
        STATE_FINISHED,
    };

    friend class P2PSocketDispatcher;

    friend class base::RefCountedThreadSafe<P2PAsyncAddressResolver>;

    virtual ~P2PAsyncAddressResolver();

    void DoSendRequest(const rtc::SocketAddress& host_name,
        const DoneCallback& done_callback);
    void DoUnregister();
    void OnResponse(const net::IPAddressList& address);
    void DeliverResponse(const net::IPAddressList& address);

    P2PSocketDispatcher* dispatcher_;
    scoped_refptr<base::SingleThreadTaskRunner> ipc_task_runner_;
    scoped_refptr<base::SingleThreadTaskRunner> delegate_task_runner_;

    // State must be accessed from delegate thread only.
    State state_;

    // Accessed on the IPC thread only.
    int32_t request_id_;
    bool registered_;
    std::vector<rtc::IPAddress> addresses_;
    DoneCallback done_callback_;

    DISALLOW_COPY_AND_ASSIGN(P2PAsyncAddressResolver);
};

} // namespace content

#endif // CONTENT_RENDERER_P2P_HOST_ADDRESS_REQUEST_H_
